Dustin's Blade 450 3D Update

[murankar]

First i would do the bec, it could be that simple. If the problem is fixed thennits the bec and project done. On the other hand if it does not work then its not the esc. Then its off to the gryo.

[Derek]

First i would do the bec, it could be that simple. If the problem is fixed then its the bec and project done. On the other hand if it does not work then its not the esc. Then its off to the gryo.

Unfortunately, I don't have any of the above items here, lol. Dustin said that he's going to ship a GP780 gyro to me. I'm still without an esc and bec. I did mention to Dustin that I'm going to order an esc and bec. He's happy!

[Derek]

I'm looking for suggestions for a replacement ESC and a suitable external BEC for Dustin's Blade 450 3D. I thought I had an esc and bec that I could use for testing but the only esc's, around 35-45amps, and the only bec's that I have are already on planes. I'd have to remove all the wiring from my planes in order to test more. I'd rather purchase a new esc and bec. That way, I wouldn't have to tear the parts from my planes and if the new parts do work, I can send them to Dustin with the helicopter.

I believe the ESC on the Blade 450 is a 35amp ESC. There is no soft start or any programming...so I would imagine just a simple 35-40amp ESC would work just fine and an inexpensive 5amp external BEC would be suitable, as well.

any thoughts?

[Derek]

I just read a Youtube comment on what's going on with the helicopter. Someone suggested to reverse the Gyro in the tx.

Perhaps I'm thinking about this wrong but wouldn't reversing the Gyro in the tx change the Gyro Mode? Instead of being Rate Mode below 50% and Heading Hold above 50%, wouldn't it then be Heading Hold below 50% and Rate Mode above 50%?

After reading that Youtube comment, I did try it. I did reverse the Gyro in the tx. The tail slider still moved properly and I had rudder movement when I moved the stick. The direction correction still worked but the tail slider would recenter after moving the tail to the left and right. It looked like Rate Mode, to me, despite the fact that the Gyro settings were still at 76.5.

[murankar]

I am not sure what that's going to do. The only thing I van think of is put it in the aire and see what happens. The only bec I have is a 10amp Castle.

I just mentioned that earlier so when you do get them.

[Derek]

yeah, I have a couple of 10amp Castle's, too. I just don't want to take one off my stuff and have to put it back on. If I can get that Scorpion ESC from you and then a 5amp BEC from Grayson Hobby or Hobby King, I think we'll be in good shape.

[DamhDearg]

Hey Derek,
have you tried spooling up the heli without the training gear? I know you said you had it on the test stand and you said the rudder worked fine? With that gyro being susceptible to vibrations maybe the training gear is messing with it.

[Derek]

No, I haven't tried the helicopter without the training gear. The way that I see it is that the helicopter should function with or without the training gear. Yes, the training gear affect the gyro, I'm sure, but the helicopter should still function properly with or without training gear. I need to get this helicopter to work with the training gear because when I do send this back to Dustin, he's going to try a few hovers with the training gear.

[DamhDearg]

Its just funny it worked on the stand but doesn't when spooling up on the landing gear, might be a way to pin point or rule out any influence from the gear.

[Derek]

well, it never occurred to me to run the helicopter all the way up on the test stand. I was testing the helicopter on the gyro stand late at night in the garage while my wife and daughter were sleeping. I wasn't sure how much noise would travel through the house, lol. I really only got to just below half throttle and the rudder was still working. Perhaps I should try it on the gyro stand as if I were to trying to get light on the skids.

I have to work my usual 12 hour shifts tonight and tomorrow so I'll try the helicopter on the gyro stand and I'll go a bit more on the power.

[DamhDearg]

Cool, hopefully the outcome points to a solution.

[pvolcko]

It sounds like you're correct on the Tx gyro reversal change: reversing put that 75% setting into the rate mode range, so you were right about the 75% being in heading hold mode before the reversal.

If you grab the two tail grips and pull outward can you still easily twist them? The fact that you have full servo movement with power down, but restricted when spun up means two options to me:

1) Mechanical binding in the tail when it is spun up, but not when it is still. Grabbing and pulling the grips outward (simulating centrifugal force) and trying to twist may reveal a notch or something in the bearings that is causing it.

2) Tx setup problem. Make sure there are no throttle->rudder or pitch->rudder mixes in there. To test: set gyro tx setting to rate mode, unplug the esc from the motor (or power up with am rx pack) and see if you have full rudder movement at bottom, middle, and top pitch/throttle positions. Make sure TH is off as that could fake out the mix, if there is one in there. If you see this odd restriction of rudder at mid stick but not at bottom and/or top stick then that's indicating a mix is hosing your efforts.

I'm not on board with the Rx power bus theory. I would expect brown outs and problems with the other servos too when spun up. You can test by simply stress testing the cyclic and tail servos. Apply some force on the swash (both up and down) while everything is in neutral position. Hold the stress for 1 minute in each direction. Servos will heat up and will draw high current from the power system, letting you know if there is an issue.

Make sure the gears in that tail servo aren't stripped, too. Might be skipping when spun up and there is some load, but fine when not spun up. Test by holding the heli by the control rod and moving the rudder stick each way. Should be able to move it without jumps or skips or anything like that. Again, powering with rx pack or disconnected motor.

[Derek]

Thanks for that, Paul! I certainly give all of that a try.

[murankar]

Yeah I read this last but was getting late and some thoughts in my head kept me from falling asleep right away.

My th9x stock firmware has an option called revo mix. From my understanding revo mix was used to controls the tail prior to gyros. If I am understanding it right this mix would give tail output based on collective input. If its not setup correctly you would get either and over correction or under correction based on collective input. If this setting is turned on or programmed it could be a cause for your tail acting the way it is. I never used it so I can't say for sure if this is what is causing your issue.

[Derek]

Yeah, I don't use Revo Mix on any of my helicopters.

[murankar]

Today we don't need to. The gyro does that for us.

[pvolcko]

Gyros usually have some option for collective and/or cyclic pre-comp for the tail. So be sure if your gyro has this to disable it to start with, too. However, revomix or precomp would be minimal around mid stick on collective so even if it were enabled at the just lifting off stage, given median collective position, the effect should be minimal. Not enough to explain this drastic difference between off/low spin vs fully spun up rudder behavior as seen in the vid.

[murankar]

Would a flybar tail gyro have pre comp?

[Tony]

Having owned a blade for some time I did know that vibrations cause havock with those gyros, but I'm sure I mentioned this weeks ago.

Take the main rotor blades off, leave flybar paddles on. You can hold heli down while you spin it up above half stick. You can feel for vibrations at this point. Might be paddles that are not balanced, or it Could be a simple case of more padding under gyro. I had 3 of those gyro pads under mine..

Is the tail spinning fast enough for the gyro to do it's work correctly, belt slipping at higher throttle!!

[Derek]

Would a flybar tail gyro have pre comp?

I'm sure this gyro has no pre comp. It's a very very basic Heading Hold tail gyro. It has a pot for setting the travel adjust and two switches...one for Analog Servo/Digital Servo and another for Rev/Nor. That's it!